EFFECT OF ENDURANCE EXERCISE ON SKELETAL MUSCLE WITH CHRONIC ALCOHOL INGESTION IN RAT

Abstract

The effect of endurance exercise training on mechanical properties of skeletal muscle with chronic ethanol ingestion was determined in this study. Three to four-week-old male Wistar rats were randomly assigned to four groups: control (CON), control with exercise (CON/EXE), ethanol (ETH), and ethanol with exercise (ETH/EXE). The CON/EXE and ETH/EXE groups were trained to run for 12 weeks on a motor driven treadmill. ETH and ETH/EXE groups were adapted to a liquid alcohol diet (Lieber–DeCarli). Tetanic, twitch force generation, specific force, fatigue time, and shortening velocity of extensor digitorum longus (EDL) and soleus muscles were tested by using an in vitro muscle testing system. Our study shows that exercise does not improve the contractile properties of skeletal muscle with chronic ethanol ingestion indicated by similar twitch force and fatigue time between ETH/EXE and ETH groups in Types I and II fibers, and by lowered tetanic and specific forces in Type I fibers in ETH/EXE group compared to ETH group, possibly due to damage induced by oxidative stress. Future studies on interaction of the biochemical changes and contractile properties of the skeletal muscle with chronic ethanol ingestion will be conducted to better understand mechanisms behind alterations in contractile properties.